Lift-bridge.



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J. L. HARRINGTON.

LIFT BRIDGE.

AI?PLIOATION FILED NOV. 7, 1910.

Patented May 28 1912.

8 SHEETS-SHEET 1.

IN VENTOR.

, WITNESSES.- A

' JohhLHar'r/hgfon BY I l I ATT6RNEY.

J. L. HARRINGTON.

LIFT BRIDGE. APPLICATION FILED N017; 1910.

Patnted May 28, 1912.

3 SHEETS-SHEET 2.

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- 11v VENTOR/ JohnLHarr/bgfon.

WITNESSES:

ATTORNEY.

J. L. HARRINGTON.

LIFT BRIDGE. YAPPLIOA'JTION FILED NOV. 1, 1 91o.

Patented May 28, 1912.

3 SHEETS-SHEET 3.

I INVENTOR.

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WITNESSES:

ATTORNEY.

UNITED STATES PATENT o'rrron.

JOHN LYLE HARRINGTON, OF'KANSAS CITY, MISSOURI.

LIFT-BRIDGE.

T0 (ZZZ QLILOI'IL it may concern Be it; known that I, Join LvLn I'IARRIXG- TON, a citizen of the United States. residing at Kansas City. in the county of Jackson and State of iIIisso n-i. have invented certain new and useful Improvements in Lift- Bridges; and I do declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being bad to the accompanying drawings, and to the let ters and figures of reference marked thereon, which form a part of this specification. My invention relates to lift bridges and more particularly to a rack and pinion mechanism for *aising and lowering the movable span in a bridge of this character.

It is the object of my invention to pr0- viderack and'pinion mechanism for bridges of this type wherein the racks are mounted on the bridge to have limited lateral move- Xment, and are constructed to afford flexibility, so that when engaged by the pinions on the lifting span, they may move slightly with the lateral movement of the span.

In order to obviate=lost motion between the racks" and pinions, I provide my pinion mechanism with'donble Wheels for engaging opposite sides of the racks, so that the parts are always held in operative relation.

A further object of my invention is to provide other improved details of structurewhich willf-be. hereinafter more fully described and illustratedin' the. accompanying drawings, wherein Figure I is a side view of a lift bridge having rack and pinion mechanism in accordance with my invention. FigaII is a plan view of a part of the bridge. Fig. III is an enlarged verspective'view of the upper mounting for the rack, Fig'IV is an enlarged perspective view of the rack bracing device. Fig. V is an enlarged edge view of a rack and. its mountings. Fig. VI is a sideview of same. Fig. VII is a longitudinal section of same, showing the overlapped construction. Fig. VIII is adetail view of the operative connection between the rack and pinions. view of same.

Referring more indetail to the parts :-1 designates the approaches, 2 the piers. 3 the towers, and at the vertically movable span of a lift bridge of ordinary construction,

Fig. IX is a plan 3 the span being connected at its, ends with Specification of Letters Patent.

Application filed November 7, I910.

Patented May728,1912.

Serial- No. 591,108.

connterpoise weights 5. through cables 6,

which run over sheaves 7 on the towers in' the ordinary manner. I Near the top of each tower. l mount a supporting frame 8 which is preferably formed of channel bars, spaced apart and projected beyond the inner vertical plane of the tower, there being one of these frames near each side of the tower and as the construction of the supporting famesthe racks and the pinion mechanisms is the same in each instance, but one will be described in detail with the understanding that such description relates equally to the rest.

Fixed to the inner faces of the channel bars of the frame 8, at the outwardly projecting end of the frame, are diaphragins 9 which space the bars apart and are also spaced from each other, as clearly illustratedin Fig. III. Supported on the appreach, directly beneath the upper frame. 8,

is a lower frame of the same construction for supporting the lower end of the rack.

10 designates the rack which is preferably formed of layers of flexible metal plates having edge teeth 11. formed therein, the plates being laid one upon the other with the joints in successive layers broken as shown in Fig. VII. Through the central part of each plate are apertures which are adapted to register when the layers are brought together, and projected through jected into the space between the dia-' phragms 9 and the channel members of the supporting frames 8, where they are pivotally mounted on a pin 16 which projects through and is carried by the diaphragms 9.

By providing the link mounting at both the top and bottom, the rack is allowed free pivotal movement within a limit controlled by the movement of the links, which is more than sufficient to allow the rack to follow the lateral movement of the lifting span.

In order to hold the rack against move ment toward the open span, I provide the rack w th a keeper bracket comprising a T-plate 19, thewings of which are rigidly and below the bodies of the T-plates 19,

each of the rack plates having a slot 20,

' through which a pin 18 is projected, so that the T-plates 19 may havefree lateral movement to theextent of the length of the slots,

while the pins 18 will hold the plates and the racks against movement into the span opening,so.that when the span is in operation the racks cannot buckle or move inwardly so as to interfere with the pinions.

I prefer to provide a rack on the towers at each corner of the movable span, .as in this manner the bridge may be balanced to better advantage, while the span is being raised or lowered, it being necessary in any event to place a rack on each tower, so that both ends of the span may be lifted or lowered together. 1

' Referring now to the pinion mechanism, 21 designates bearings on the span 4, such bearings being arranged in pairs and in parallel planes. ings is a drive shaft 22 which is connected by suitable transmission with a motor 23 of any ordinary type. The end of shaft 22 extends past and adjacent to the rack 10 and has rigidly fixed to its free end'apinion 25 which engages the rack teeth. Journaled in the other set of bearings 21 is an axle 24 which extends past'and adjacent to the edge of rack 10 opposite the main drive shaft and has rigidly fixed to its free end a pinion 25, which engages the teeth on the edge of rack 10 opposite the pinion 25. Fixed to the drive shaft 22 and axle 24 are driving gears 26 and27 which transmit power from -the 'main shaft to the axle 24, so that when the shaft is in motion the pinions may be revolved in unison and work against opposite edges of the rack to lift the span.

By providing the double pinions, constant engagement with the rack 1s insured and it is impossible for the rack to spread from the pinions irrespective of the lateral motion of the span or rack.

It is apparent that-a set of pinions is provided at each corner of the spanto cooperate with the racks on the towers and that these pinions may be operated from a common motor.

Inasmuch as the operation of the span is apparent from the drawings and description of the mechanical construction of the parts, it is unnecessary to describe same in detail.

Journaled in one set of bear-' the racks, and means Having thus described my invention, what 'I claim as new therein and desire to secure by Letters-Patent is 1. A lift bridge comprising towers and a vertically movable span, racks having linked pivotal mounting on the towers, to afford limited lateral movement thereof relative to the span, pinions on the span engaging said racks, and means for actuating-said inions.

2. A lift bridge comprising towers and a vertically movable span, racks arranged vertically on the towers and having linked connection therewith to afiord limited lateral movement thereof, relative to the span, pinions carried by the span and engaging said racks, and means for actuating sald inions.

3. In a lift bridge, towers and avertically movable span, frames carried by the towers and projecting into the span opening, links pivotally mounted on said frames, racks pivotally connected with said links, pinions on the span engaging said racks, and means for actuating said pinions.

4. In a lift bridge, towers and a vertically movable span, frames carried by said towers and comprising spaced members, diaphragms supported by said spaced members and separated to form a chamber, a pin carried by said dia'phragms and extending through said chamber, links pivotally mounted on said pin, racks pivotally con nected with said links, pinions carried by said span and engaging said racks, andmeans for actuating said pinions.

5. In a lift bridge, towers and a vertically movable span, flexible racks carried by the towers, pinions on the span engaging said racks, plates on the towers and on the racks, and pin and slot connection. between said plates for permitting lateral movement of for actuating said pinions. v v

6. In a lift bridge, towers and a vertically movable span, racks pivoted on said towers to have limited lateral movement relative to the span, plates on said towers having lateral slots therein, plates fixed on the racks and having pins projecting into: the slots in the tower plates, pinions 'on said span engaging said racks, and means for actuating said pinions.

7. In a lift bridge, towers and a vertically movable span, racks pivoted at their upper and lower ends to towers to have limited lateral movement relative to the span, plates fixed to said towers and arranged in pairs, the members of said pairs having registering lateral slots, plates fixed on the racks and projecting between the tower plates, pins on the rack plates extending into the slots in the tower plates, pinions on said span engaging said racks, and means for actuating said pinions.

, movable span, racks pivoted at their upper and lower ends to towers to have limited lateral movement relative to the span, plates fixed to said towers, plates havlng wings fixed to the racks and having'body portions overlapping the tower plates, pin and slot connection between the tower and rack plates to permit lateral movement of the racks, the parts of the rack plates being cut to follow the contour of the rack teeth and the bodies of the rack plates being extended from the faces of the rack teeth, pinions on said span engaging said racks, and means for actuating said pinlons.

9. In a lift brldge, towers and a vertically movable span, upper and lower frames on the towers, each of said frames comprising spaced members having diaphragms separated to form chambers, the upper and lower frames being arranged in pairs, pins ex tending through said diaphragm, links pivotally mounted on said pins, racks having their upperand lower ends pivotally connected with said links, means on the towers for holding said racks against movement in theedirection of the span, although permitting limited lateral movement thereof, pinions on the span arranged in pairs, the members ofeach pair engaging opposite sides of one of the tower racks, and means for actuating said pinions.

In testimony whereof I aflix my signature in presence of two witnesses. JOHN LYLE HARRINGTON. Vitnesses:

llilYRTLE M. JACKSON, ARTHUR W. CAPS. 

